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TY - CONF AU - Shibata, T. AU - Ikegami, K. AU - Liu, Y. AU - Miura, A. AU - Naito, F. AU - Nanmo, K. AU - Oguri, H. AU - Ohkoshi, K. AU - Otani, M. AU - Shinto, K. AU - Takagi, A. ED - Pei, Guoxi ED - Schaa, Volker RW ED - Chin, Yong Ho ED - Fu, Shinian ED - Zhao, Ning TI - Numerical and Experimental Study of H⁻ Beam Dynamics in J-PARC LEBT J2 - Proc. of LINAC2018, Beijing, China, 16-21 September 2018 CY - Beijing, China T2 - Linear Accelerator Conference T3 - 29 LA - english AB - Negative hydrogen ion (H⁻) beam dynamics in J-PARC Low Energy Beam Transport (LEBT) has been investigated by numerical modeling which calculates particle transport with effect of space charge and collision processes. Understandings of H⁻ beam transport in LEBT is important for high transmission rate from Ion Source (IS) to Radio Frequency Quadrupole (RFQ) in J-PARC in higher beam current in future. In 2017, 45 mA beam current of H⁻ has been extracted from IS in J-PARC user operation which has been increased from 30 mA in last 2 years. The beam current is planned to be increased to 50 mA in the next upgrade. As the beam current increase, IS/LEBT commissioning becomes more difficult because of the higher space charge (SC). Especially in J-PARC, vacuum pressure is around 10⁻⁵ Pa by 15 mmf orifice located in the center of LEBT. The orifice prevents residual gas injection from IS to LEBT/RFQ and thus produces stronger SC effect. In the presentation, numerical results are compared with actual results from J-PARC Linac beam commissioning. A comparison of the results shows that location of the 15 mmf orifice results in two peaks of RFQ transmission rate against SOL currents. PB - JACoW Publishing CP - Geneva, Switzerland SP - 519 EP - 521 KW - rfq KW - MMI KW - linac KW - emittance KW - solenoid DA - 2019/01 PY - 2019 SN - 2226-0366 SN - 978-3-95450-194-6 DO - DOI: 10.18429/JACoW-LINAC2018-TUPO079 UR - http://jacow.org/linac2018/papers/tupo079.pdf ER -